The subject matter of this disclosure is generally related to data storage systems that are used to maintain large data sets for supporting multiple host applications and concurrent users. Host applications, including but not limited to file servers, block servers and databases, may run on a server in a server cluster. Storage arrays may be used to maintain data for the host applications. Each storage array may include multiple computing nodes that manage access to tangible persistent data storage devices on which host application data is maintained. There are typically multiple levels at which host application data may be cached in volatile memory between the storage array and the host server, where different levels have different proximity to the processor of the host server. Proximity of host application data to the host server processor may be directly related to host application performance because the rate at which a processor can process host application data may be limited by the rate at which that data can be provided to the processor. A variety of techniques exist for managing use of the limited volatile memory resources that are available with close proximity to the host server processor.